An X-ray computed tomography imaging apparatus includes an X-ray tube that generates X-rays. Before scan, to maintain the cleanliness in the X-ray tube or raise the temperature of components such as a rotating anode in the X-ray tube to a predetermined value or more, the X-ray tube is warmed up by applying a high voltage and supplying a filament heating current.
Since the warm-up is performed using a cathode used for scan, the life of the cathode may be shortened by the application purpose other than scan. In addition, since the size of a focus is fixed, the surface of the anode may roughen.